Props to you for making something in Java; a language I'm really interested and intend to learn in the future. If you're looking for sprites, tiles, etc ripped from the games, might I suggest The Spriter's Resource? They have quite the extensive sprite collection for the Pokemon series.

Yeah thank you, i have already seen that site, but im more interested in custom sprites, such as new trainers which have graphics too, as in this game you are going to be able to customise your character so not every single person looks the same.